Merge branch 'develop' into v2

CHANGELOG.md

@@ -1,19 +1,5 @@
 # Changelog
 
-## v1.6.2
-### Fixed
-* Fixes file upload size not being properly enforced.
-* Fixes a bug that prevented listing a directory when it contained a named pipe. Also added a check to prevent attempting to read a named pipe directly.
-* Fixes a bug with the archiver logic that would include folders that had the same name prefix. (for example, requesting only `map` would also include `map2` and `map3`)
-* Requests to the Panel that return a client error (4xx response code) no longer trigger an exponential backoff, they immediately stop the request.
-
-### Changed
-* CPU limit fields are only set on the Docker container if they have been specified for the server — otherwise they are left empty.
-
-### Added
-* Added the ability to define the location of the temporary folder used by Wings — defaults to `/tmp/pterodactyl`.
-* Adds the ability to authenticate for SFTP using public keys (requires `Panel@1.8.0`).
-
 ## v1.6.1
 ### Fixed
 * Fixes error that would sometimes occur when starting a server that would cause the temporary power action lock to never be released due to a blocked channel.

cmd/root.go

@@ -9,11 +9,13 @@ import (
 	"net/http"
 	_ "net/http/pprof"
 	"os"
+	"os/signal"
 	"path"
 	"path/filepath"
 	"runtime"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/NYTimes/logrotate"
@@ -28,6 +30,7 @@ import (
 
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
+	"github.com/pterodactyl/wings/internal/notify"
 	"github.com/pterodactyl/wings/loggers/cli"
 	"github.com/pterodactyl/wings/remote"
 	"github.com/pterodactyl/wings/router"
@@ -324,6 +327,7 @@ func rootCmdRun(cmd *cobra.Command, _ []string) {
 	}
 
 	// Check if the server should run with TLS but using autocert.
+	go func(s *http.Server, api config.ApiConfiguration, sys config.SystemConfiguration, autotls bool, tlshostname string) {
 		if autotls {
 			m := autocert.Manager{
 				Prompt:     autocert.AcceptTOS,
@@ -362,6 +366,19 @@ func rootCmdRun(cmd *cobra.Command, _ []string) {
 		if err := s.ListenAndServe(); err != nil {
 			log.WithField("error", err).Fatal("failed to configure HTTP server")
 		}
+	}(s, api, sys, autotls, tlshostname)
+
+	if err := notify.Readiness(); err != nil {
+		log.WithField("error", err).Error("failed to notify systemd of readiness state")
+	}
+
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
+	<-c
+
+	if err := notify.Stopping(); err != nil {
+		log.WithField("error", err).Error("failed to notify systemd of stopping state")
+	}
 }
 
 // Reads the configuration from the disk and then sets up the global singleton

environment/docker/container.go

@@ -480,3 +480,21 @@ func (e *Environment) convertMounts() []mount.Mount {
 
 	return out
 }
+
+func (e *Environment) resources() container.Resources {
+	l := e.Configuration.Limits()
+	pids := l.ProcessLimit()
+
+	return container.Resources{
+		Memory:            l.BoundedMemoryLimit(),
+		MemoryReservation: l.MemoryLimit * 1_000_000,
+		MemorySwap:        l.ConvertedSwap(),
+		CPUQuota:          l.ConvertedCpuLimit(),
+		CPUPeriod:         100_000,
+		CPUShares:         1024,
+		BlkioWeight:       l.IoWeight,
+		OomKillDisable:    &l.OOMDisabled,
+		CpusetCpus:        l.Threads,
+		PidsLimit:         &pids,
+	}
+}

environment/settings.go

@@ -99,36 +99,21 @@ func (l Limits) ProcessLimit() int64 {
 	return config.Get().Docker.ContainerPidLimit
 }
 
-// AsContainerResources returns the available resources for a container in a format
-// that Docker understands.
 func (l Limits) AsContainerResources() container.Resources {
 	pids := l.ProcessLimit()
-	resources := container.Resources{
+
+	return container.Resources{
 		Memory:            l.BoundedMemoryLimit(),
 		MemoryReservation: l.MemoryLimit * 1_000_000,
 		MemorySwap:        l.ConvertedSwap(),
+		CPUQuota:          l.ConvertedCpuLimit(),
+		CPUPeriod:         100_000,
+		CPUShares:         1024,
 		BlkioWeight:       l.IoWeight,
 		OomKillDisable:    &l.OOMDisabled,
+		CpusetCpus:        l.Threads,
 		PidsLimit:         &pids,
 	}
-
-	// If the CPU Limit is not set, don't send any of these fields through. Providing
-	// them seems to break some Java services that try to read the available processors.
-	//
-	// @see https://github.com/pterodactyl/panel/issues/3988
-	if l.CpuLimit > 0 {
-		resources.CPUQuota = l.CpuLimit * 1_000
-		resources.CPUPeriod = 100_00
-		resources.CPUShares = 1024
-	}
-
-	// Similar to above, don't set the specific assigned CPUs if we didn't actually limit
-	// the server to any of them.
-	if l.Threads != "" {
-		resources.CpusetCpus = l.Threads
-	}
-
-	return resources
 }
 
 type Variables map[string]interface{}

internal/notify/notify.go

@@ -0,0 +1,19 @@
+// Package notify handles notifying the operating system of the program's state.
+//
+// For linux based operating systems, this is done through the systemd socket
+// set by "NOTIFY_SOCKET" environment variable.
+//
+// Currently, no other operating systems are supported.
+package notify
+
+func Readiness() error {
+	return readiness()
+}
+
+func Reloading() error {
+	return reloading()
+}
+
+func Stopping() error {
+	return stopping()
+}

internal/notify/notify_linux.go

@@ -0,0 +1,48 @@
+package notify
+
+import (
+	"io"
+	"net"
+	"os"
+	"strings"
+)
+
+func notify(path string, r io.Reader) error {
+	s := &net.UnixAddr{
+		Name: path,
+		Net:  "unixgram",
+	}
+	c, err := net.DialUnix(s.Net, nil, s)
+	if err != nil {
+		return err
+	}
+	defer c.Close()
+
+	if _, err := io.Copy(c, r); err != nil {
+		return err
+	}
+	return nil
+}
+
+func socketNotify(payload string) error {
+	v, ok := os.LookupEnv("NOTIFY_SOCKET")
+	if !ok || v == "" {
+		return nil
+	}
+	if err := notify(v, strings.NewReader(payload)); err != nil {
+		return err
+	}
+	return nil
+}
+
+func readiness() error {
+	return socketNotify("READY=1")
+}
+
+func reloading() error {
+	return socketNotify("RELOADING=1")
+}
+
+func stopping() error {
+	return socketNotify("STOPPING=1")
+}

internal/notify/notify_other.go

@@ -0,0 +1,16 @@
+//go:build !linux
+// +build !linux
+
+package notify
+
+func readiness() error {
+	return nil
+}
+
+func reloading() error {
+	return nil
+}
+
+func stopping() error {
+	return nil
+}

remote/http.go

@@ -142,10 +142,12 @@ func (c *client) request(ctx context.Context, method, path string, body io.Reade
 		if r.HasError() {
 			// Close the request body after returning the error to free up resources.
 			defer r.Body.Close()
-			// Don't keep attempting to access this endpoint if the response is a 4XX
-			// level error which indicates a client mistake. Only retry when the error
-			// is due to a server issue (5XX error).
-			if r.StatusCode >= 400 && r.StatusCode < 500 {
+			// Don't keep spamming the endpoint if we've already made too many requests or
+			// if we're not even authenticated correctly. Retrying generally won't fix either
+			// of these issues.
+			if r.StatusCode == http.StatusForbidden ||
+				r.StatusCode == http.StatusTooManyRequests ||
+				r.StatusCode == http.StatusUnauthorized {
 				return backoff.Permanent(r.Error())
 			}
 			return r.Error()

remote/types.go

@@ -11,11 +11,6 @@ import (
 	"github.com/pterodactyl/wings/parser"
 )
 
-const (
-	SftpAuthPassword  = SftpAuthRequestType("password")
-	SftpAuthPublicKey = SftpAuthRequestType("public_key")
-)
-
 // A generic type allowing for easy binding use when making requests to API
 // endpoints that only expect a singular argument or something that would not
 // benefit from being a typed struct.
@@ -68,17 +63,15 @@ type RawServerData struct {
 	ProcessConfiguration json.RawMessage `json:"process_configuration"`
 }
 
-type SftpAuthRequestType string
-
 // SftpAuthRequest defines the request details that are passed along to the Panel
 // when determining if the credentials provided to Wings are valid.
 type SftpAuthRequest struct {
-	Type          SftpAuthRequestType `json:"type"`
 	User          string `json:"username"`
 	Pass          string `json:"password"`
 	IP            string `json:"ip"`
 	SessionID     []byte `json:"session_id"`
 	ClientVersion []byte `json:"client_version"`
+	Type          string `json:"type"`
 }
 
 // SftpAuthResponse is returned by the Panel when a pair of SFTP credentials
@@ -86,6 +79,7 @@ type SftpAuthRequest struct {
 // matched as well as the permissions that are assigned to the authenticated
 // user for the SFTP subsystem.
 type SftpAuthResponse struct {
+	SSHKeys     []string `json:"ssh_keys"`
 	Server      string   `json:"server"`
 	Permissions []string `json:"permissions"`
 }

router/router_server_files.go

@@ -37,15 +37,6 @@ func getServerFileContents(c *gin.Context) {
 		return
 	}
 	defer f.Close()
-	// Don't allow a named pipe to be opened.
-	//
-	// @see https://github.com/pterodactyl/panel/issues/4059
-	if st.Mode()&os.ModeNamedPipe != 0 {
-		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
-			"error": "Cannot open files of this type.",
-		})
-		return
-	}
 
 	c.Header("X-Mime-Type", st.Mimetype)
 	c.Header("Content-Length", strconv.Itoa(int(st.Size())))
@@ -131,10 +122,6 @@ func putServerRenameFiles(c *gin.Context) {
 					// Return nil if the error is an is not exists.
 					// NOTE: os.IsNotExist() does not work if the error is wrapped.
 					if errors.Is(err, os.ErrNotExist) {
-						s.Log().WithField("error", err).
-							WithField("from_path", pf).
-							WithField("to_path", pt).
-							Warn("failed to rename: source or target does not exist")
 						return nil
 					}
 					return err

router/websocket/listeners.go

@@ -164,6 +164,5 @@ func (h *Handler) listenForServerEvents(ctx context.Context) error {
 	if err != nil {
 		return errors.WithStack(err)
 	}
-
 	return nil
 }

server/filesystem/archive.go

@@ -130,7 +130,7 @@ func (a *Archive) withFilesCallback(tw *tar.Writer) func(path string, de *godirw
 		for _, f := range a.Files {
 			// If the given doesn't match, or doesn't have the same prefix continue
 			// to the next item in the loop.
-			if p != f && !strings.HasPrefix(strings.TrimSuffix(p, "/")+"/", f) {
+			if p != f && !strings.HasPrefix(p, f) {
 				continue
 			}
 

server/filesystem/filesystem.go

@@ -115,6 +115,19 @@ func (fs *Filesystem) Touch(p string, flag int) (*os.File, error) {
 	return f, nil
 }
 
+// Reads a file on the system and returns it as a byte representation in a file
+// reader. This is not the most memory efficient usage since it will be reading the
+// entirety of the file into memory.
+func (fs *Filesystem) Readfile(p string, w io.Writer) error {
+	file, _, err := fs.File(p)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	_, err = bufio.NewReader(file).WriteTo(w)
+	return err
+}
+
 // Writefile writes a file to the system. If the file does not already exist one
 // will be created. This will also properly recalculate the disk space used by
 // the server when writing new files or modifying existing ones.
@@ -171,16 +184,16 @@ func (fs *Filesystem) CreateDirectory(name string, p string) error {
 	return os.MkdirAll(cleaned, 0o755)
 }
 
-// Rename moves (or renames) a file or directory.
+// Moves (or renames) a file or directory.
 func (fs *Filesystem) Rename(from string, to string) error {
 	cleanedFrom, err := fs.SafePath(from)
 	if err != nil {
-		return errors.WithStack(err)
+		return err
 	}
 
 	cleanedTo, err := fs.SafePath(to)
 	if err != nil {
-		return errors.WithStack(err)
+		return err
 	}
 
 	// If the target file or directory already exists the rename function will fail, so just
@@ -202,10 +215,7 @@ func (fs *Filesystem) Rename(from string, to string) error {
 		}
 	}
 
-	if err := os.Rename(cleanedFrom, cleanedTo); err != nil {
-		return errors.WithStack(err)
-	}
-	return nil
+	return os.Rename(cleanedFrom, cleanedTo)
 }
 
 // Recursively iterates over a file or directory and sets the permissions on all of the
@@ -482,11 +492,7 @@ func (fs *Filesystem) ListDirectory(p string) ([]Stat, error) {
 					cleanedp, _ = fs.SafePath(filepath.Join(cleaned, f.Name()))
 				}
 
-				// Don't try to detect the type on a pipe — this will just hang the application and
-				// you'll never get a response back.
-				//
-				// @see https://github.com/pterodactyl/panel/issues/4059
-				if cleanedp != "" && f.Mode()&os.ModeNamedPipe == 0 {
+				if cleanedp != "" {
 					m, _ = mimetype.DetectFile(filepath.Join(cleaned, f.Name()))
 				} else {
 					// Just pass this for an unknown type because the file could not safely be resolved within

server/filesystem/filesystem_test.go

@@ -1,7 +1,6 @@
 package filesystem
 
 import (
-	"bufio"
 	"bytes"
 	"errors"
 	"math/rand"
@@ -45,14 +44,6 @@ type rootFs struct {
 	root string
 }
 
-func getFileContent(file *os.File) string {
-	var w bytes.Buffer
-	if _, err := bufio.NewReader(file).WriteTo(&w); err != nil {
-		panic(err)
-	}
-	return w.String()
-}
-
 func (rfs *rootFs) CreateServerFile(p string, c []byte) error {
 	f, err := os.Create(filepath.Join(rfs.root, "/server", p))
 
@@ -84,6 +75,54 @@ func (rfs *rootFs) reset() {
 	}
 }
 
+func TestFilesystem_Readfile(t *testing.T) {
+	g := Goblin(t)
+	fs, rfs := NewFs()
+
+	g.Describe("Readfile", func() {
+		buf := &bytes.Buffer{}
+
+		g.It("opens a file if it exists on the system", func() {
+			err := rfs.CreateServerFileFromString("test.txt", "testing")
+			g.Assert(err).IsNil()
+
+			err = fs.Readfile("test.txt", buf)
+			g.Assert(err).IsNil()
+			g.Assert(buf.String()).Equal("testing")
+		})
+
+		g.It("returns an error if the file does not exist", func() {
+			err := fs.Readfile("test.txt", buf)
+			g.Assert(err).IsNotNil()
+			g.Assert(errors.Is(err, os.ErrNotExist)).IsTrue()
+		})
+
+		g.It("returns an error if the \"file\" is a directory", func() {
+			err := os.Mkdir(filepath.Join(rfs.root, "/server/test.txt"), 0o755)
+			g.Assert(err).IsNil()
+
+			err = fs.Readfile("test.txt", buf)
+			g.Assert(err).IsNotNil()
+			g.Assert(IsErrorCode(err, ErrCodeIsDirectory)).IsTrue()
+		})
+
+		g.It("cannot open a file outside the root directory", func() {
+			err := rfs.CreateServerFileFromString("/../test.txt", "testing")
+			g.Assert(err).IsNil()
+
+			err = fs.Readfile("/../test.txt", buf)
+			g.Assert(err).IsNotNil()
+			g.Assert(IsErrorCode(err, ErrCodePathResolution)).IsTrue()
+		})
+
+		g.AfterEach(func() {
+			buf.Truncate(0)
+			atomic.StoreInt64(&fs.diskUsed, 0)
+			rfs.reset()
+		})
+	})
+}
+
 func TestFilesystem_Writefile(t *testing.T) {
 	g := Goblin(t)
 	fs, rfs := NewFs()
@@ -101,10 +140,9 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err := fs.Writefile("test.txt", r)
 			g.Assert(err).IsNil()
 
-			f, _, err := fs.File("test.txt")
+			err = fs.Readfile("test.txt", buf)
 			g.Assert(err).IsNil()
-			defer f.Close()
-			g.Assert(getFileContent(f)).Equal("test file content")
+			g.Assert(buf.String()).Equal("test file content")
 			g.Assert(atomic.LoadInt64(&fs.diskUsed)).Equal(r.Size())
 		})
 
@@ -114,10 +152,9 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err := fs.Writefile("/some/nested/test.txt", r)
 			g.Assert(err).IsNil()
 
-			f, _, err := fs.File("/some/nested/test.txt")
+			err = fs.Readfile("/some/nested/test.txt", buf)
 			g.Assert(err).IsNil()
-			defer f.Close()
-			g.Assert(getFileContent(f)).Equal("test file content")
+			g.Assert(buf.String()).Equal("test file content")
 		})
 
 		g.It("can create a new file inside a nested directory without a trailing slash", func() {
@@ -126,10 +163,9 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err := fs.Writefile("some/../foo/bar/test.txt", r)
 			g.Assert(err).IsNil()
 
-			f, _, err := fs.File("foo/bar/test.txt")
+			err = fs.Readfile("foo/bar/test.txt", buf)
 			g.Assert(err).IsNil()
-			defer f.Close()
-			g.Assert(getFileContent(f)).Equal("test file content")
+			g.Assert(buf.String()).Equal("test file content")
 		})
 
 		g.It("cannot create a file outside the root directory", func() {
@@ -154,6 +190,28 @@ func TestFilesystem_Writefile(t *testing.T) {
 			g.Assert(IsErrorCode(err, ErrCodeDiskSpace)).IsTrue()
 		})
 
+		/*g.It("updates the total space used when a file is appended to", func() {
+			atomic.StoreInt64(&fs.diskUsed, 100)
+
+			b := make([]byte, 100)
+			_, _ = rand.Read(b)
+
+			r := bytes.NewReader(b)
+			err := fs.Writefile("test.txt", r)
+			g.Assert(err).IsNil()
+			g.Assert(atomic.LoadInt64(&fs.diskUsed)).Equal(int64(200))
+
+			// If we write less data than already exists, we should expect the total
+			// disk used to be decremented.
+			b = make([]byte, 50)
+			_, _ = rand.Read(b)
+
+			r = bytes.NewReader(b)
+			err = fs.Writefile("test.txt", r)
+			g.Assert(err).IsNil()
+			g.Assert(atomic.LoadInt64(&fs.diskUsed)).Equal(int64(150))
+		})*/
+
 		g.It("truncates the file when writing new contents", func() {
 			r := bytes.NewReader([]byte("original data"))
 			err := fs.Writefile("test.txt", r)
@@ -163,10 +221,9 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err = fs.Writefile("test.txt", r)
 			g.Assert(err).IsNil()
 
-			f, _, err := fs.File("test.txt")
+			err = fs.Readfile("test.txt", buf)
 			g.Assert(err).IsNil()
-			defer f.Close()
-			g.Assert(getFileContent(f)).Equal("new data")
+			g.Assert(buf.String()).Equal("new data")
 		})
 
 		g.AfterEach(func() {

server/filesystem/path_test.go

@@ -119,6 +119,16 @@ func TestFilesystem_Blocks_Symlinks(t *testing.T) {
 		panic(err)
 	}
 
+	g.Describe("Readfile", func() {
+		g.It("cannot read a file symlinked outside the root", func() {
+			b := bytes.Buffer{}
+
+			err := fs.Readfile("symlinked.txt", &b)
+			g.Assert(err).IsNotNil()
+			g.Assert(IsErrorCode(err, ErrCodePathResolution)).IsTrue()
+		})
+	})
+
 	g.Describe("Writefile", func() {
 		g.It("cannot write to a file symlinked outside the root", func() {
 			r := bytes.NewReader([]byte("testing"))

sftp/handler.go

@@ -125,7 +125,7 @@ func (h *Handler) Filewrite(request *sftp.Request) (io.WriterAt, error) {
 	return f, nil
 }
 
-// Filecmd hander for basic SFTP system calls related to files, but not anything to do with reading
+// Filecmd handler for basic SFTP system calls related to files, but not anything to do with reading
 // or writing to those files.
 func (h *Handler) Filecmd(request *sftp.Request) error {
 	if h.ro {

sftp/server.go

@@ -1,11 +1,17 @@
 package sftp
 
 import (
+	"bytes"
 	"context"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/elliptic"
 	"crypto/rand"
+	"crypto/rsa"
 	"crypto/x509"
 	"encoding/pem"
 	"io"
+	"io/ioutil"
 	"net"
 	"os"
 	"path"
@@ -16,7 +22,6 @@ import (
 	"emperror.dev/errors"
 	"github.com/apex/log"
 	"github.com/pkg/sftp"
-	"golang.org/x/crypto/ed25519"
 	"golang.org/x/crypto/ssh"
 
 	"github.com/pterodactyl/wings/config"
@@ -51,18 +56,7 @@ func New(m *server.Manager) *SFTPServer {
 // SFTP connections. This will automatically generate an ED25519 key if one does
 // not already exist on the system for host key verification purposes.
 func (c *SFTPServer) Run() error {
-	if _, err := os.Stat(c.PrivateKeyPath()); os.IsNotExist(err) {
-		if err := c.generateED25519PrivateKey(); err != nil {
-			return err
-		}
-	} else if err != nil {
-		return errors.Wrap(err, "sftp: could not stat private key file")
-	}
-	pb, err := os.ReadFile(c.PrivateKeyPath())
-	if err != nil {
-		return errors.Wrap(err, "sftp: could not read private key file")
-	}
-	private, err := ssh.ParsePrivateKey(pb)
+	keys, err := c.loadPrivateKeys()
 	if err != nil {
 		return err
 	}
@@ -70,23 +64,20 @@ func (c *SFTPServer) Run() error {
 	conf := &ssh.ServerConfig{
 		NoClientAuth:      false,
 		MaxAuthTries:      6,
-		PasswordCallback: func(conn ssh.ConnMetadata, password []byte) (*ssh.Permissions, error) {
-			return c.makeCredentialsRequest(conn, remote.SftpAuthPassword, string(password))
-		},
-		PublicKeyCallback: func(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
-			return c.makeCredentialsRequest(conn, remote.SftpAuthPublicKey, string(ssh.MarshalAuthorizedKey(key)))
-		},
+		PasswordCallback:  c.passwordCallback,
+		PublicKeyCallback: c.publicKeyCallback,
+	}
+
+	for _, k := range keys {
+		conf.AddHostKey(k)
 	}
-	conf.AddHostKey(private)
 
 	listener, err := net.Listen("tcp", c.Listen)
 	if err != nil {
 		return err
 	}
 
-	public := string(ssh.MarshalAuthorizedKey(private.PublicKey()))
-	log.WithField("listen", c.Listen).WithField("public_key", strings.Trim(public, "\n")).Info("sftp server listening for connections")
-
+	log.WithField("listen", c.Listen).Info("sftp server listening for connections")
 	for {
 		if conn, _ := listener.Accept(); conn != nil {
 			go func(conn net.Conn) {
@@ -112,7 +103,7 @@ func (c *SFTPServer) AcceptInbound(conn net.Conn, config *ssh.ServerConfig) {
 		// If its not a session channel we just move on because its not something we
 		// know how to handle at this point.
 		if ch.ChannelType() != "session" {
-			ch.Reject(ssh.UnknownChannelType, "unknown channel type")
+			_ = ch.Reject(ssh.UnknownChannelType, "unknown channel type")
 			continue
 		}
 
@@ -126,7 +117,7 @@ func (c *SFTPServer) AcceptInbound(conn net.Conn, config *ssh.ServerConfig) {
 				// Channels have a type that is dependent on the protocol. For SFTP
 				// this is "subsystem" with a payload that (should) be "sftp". Discard
 				// anything else we receive ("pty", "shell", etc)
-				req.Reply(req.Type == "subsystem" && string(req.Payload[4:]) == "sftp", nil)
+				_ = req.Reply(req.Type == "subsystem" && string(req.Payload[4:]) == "sftp", nil)
 			}
 		}(requests)
 
@@ -144,6 +135,7 @@ func (c *SFTPServer) AcceptInbound(conn net.Conn, config *ssh.ServerConfig) {
 			return s.ID() == uuid
 		})
 		if srv == nil {
+			_ = conn.Close()
 			continue
 		}
 
@@ -151,48 +143,172 @@ func (c *SFTPServer) AcceptInbound(conn net.Conn, config *ssh.ServerConfig) {
 		// them access to the underlying filesystem.
 		handler := sftp.NewRequestServer(channel, NewHandler(sconn, srv).Handlers())
 		if err := handler.Serve(); err == io.EOF {
-			handler.Close()
+			_ = handler.Close()
 		}
 	}
 }
 
-// Generates a new ED25519 private key that is used for host authentication when
-// a user connects to the SFTP server.
-func (c *SFTPServer) generateED25519PrivateKey() error {
-	_, priv, err := ed25519.GenerateKey(rand.Reader)
-	if err != nil {
-		return errors.Wrap(err, "sftp: failed to generate ED25519 private key")
+func (c *SFTPServer) loadPrivateKeys() ([]ssh.Signer, error) {
+	if _, err := os.Stat(path.Join(c.BasePath, ".sftp/id_rsa")); err != nil {
+		if !os.IsNotExist(err) {
+			return nil, err
 		}
-	if err := os.MkdirAll(path.Dir(c.PrivateKeyPath()), 0o755); err != nil {
-		return errors.Wrap(err, "sftp: could not create internal sftp data directory")
+
+		if err := c.generateRSAPrivateKey(); err != nil {
+			return nil, err
 		}
-	o, err := os.OpenFile(c.PrivateKeyPath(), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o600)
+	}
+	rsaBytes, err := ioutil.ReadFile(path.Join(c.BasePath, ".sftp/id_rsa"))
 	if err != nil {
-		return errors.WithStack(err)
+		return nil, errors.Wrap(err, "sftp/server: could not read private key file")
+	}
+	rsaPrivateKey, err := ssh.ParsePrivateKey(rsaBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := os.Stat(path.Join(c.BasePath, ".sftp/id_ecdsa")); err != nil {
+		if !os.IsNotExist(err) {
+			return nil, err
+		}
+
+		if err := c.generateECDSAPrivateKey(); err != nil {
+			return nil, err
+		}
+	}
+	ecdsaBytes, err := ioutil.ReadFile(path.Join(c.BasePath, ".sftp/id_ecdsa"))
+	if err != nil {
+		return nil, errors.Wrap(err, "sftp/server: could not read private key file")
+	}
+	ecdsaPrivateKey, err := ssh.ParsePrivateKey(ecdsaBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := os.Stat(path.Join(c.BasePath, ".sftp/id_ed25519")); err != nil {
+		if !os.IsNotExist(err) {
+			return nil, err
+		}
+
+		if err := c.generateEd25519PrivateKey(); err != nil {
+			return nil, err
+		}
+	}
+	ed25519Bytes, err := ioutil.ReadFile(path.Join(c.BasePath, ".sftp/id_ed25519"))
+	if err != nil {
+		return nil, errors.Wrap(err, "sftp/server: could not read private key file")
+	}
+	ed25519PrivateKey, err := ssh.ParsePrivateKey(ed25519Bytes)
+	if err != nil {
+		return nil, err
+	}
+
+	return []ssh.Signer{
+		rsaPrivateKey,
+		ecdsaPrivateKey,
+		ed25519PrivateKey,
+	}, nil
+}
+
+// generateRSAPrivateKey generates a RSA-4096 private key that will be used by the SFTP server.
+func (c *SFTPServer) generateRSAPrivateKey() error {
+	key, err := rsa.GenerateKey(rand.Reader, 4096)
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(path.Dir(c.PrivateKeyPath("rsa")), 0o755); err != nil {
+		return errors.Wrap(err, "sftp/server: could not create .sftp directory")
+	}
+	o, err := os.OpenFile(c.PrivateKeyPath("rsa"), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o600)
+	if err != nil {
+		return err
 	}
 	defer o.Close()
 
-	b, err := x509.MarshalPKCS8PrivateKey(priv)
-	if err != nil {
-		return errors.Wrap(err, "sftp: failed to marshal private key into bytes")
-	}
-	if err := pem.Encode(o, &pem.Block{Type: "PRIVATE KEY", Bytes: b}); err != nil {
-		return errors.Wrap(err, "sftp: failed to write ED25519 private key to disk")
+	if err := pem.Encode(o, &pem.Block{
+		Type:  "RSA PRIVATE KEY",
+		Bytes: x509.MarshalPKCS1PrivateKey(key),
+	}); err != nil {
+		return err
 	}
 	return nil
 }
 
-func (c *SFTPServer) makeCredentialsRequest(conn ssh.ConnMetadata, t remote.SftpAuthRequestType, p string) (*ssh.Permissions, error) {
+// generateECDSAPrivateKey generates a ECDSA-P256 private key that will be used by the SFTP server.
+func (c *SFTPServer) generateECDSAPrivateKey() error {
+	key, err := ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(path.Dir(c.PrivateKeyPath("ecdsa")), 0o755); err != nil {
+		return errors.Wrap(err, "sftp/server: could not create .sftp directory")
+	}
+	o, err := os.OpenFile(c.PrivateKeyPath("ecdsa"), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o600)
+	if err != nil {
+		return err
+	}
+	defer o.Close()
+
+	privBytes, err := x509.MarshalPKCS8PrivateKey(key)
+	if err != nil {
+		return err
+	}
+
+	if err := pem.Encode(o, &pem.Block{
+		Type:  "PRIVATE KEY",
+		Bytes: privBytes,
+	}); err != nil {
+		return err
+	}
+	return nil
+}
+
+// generateEd25519PrivateKey generates an ed25519 private key that will be used by the SFTP server.
+func (c *SFTPServer) generateEd25519PrivateKey() error {
+	_, key, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(path.Dir(c.PrivateKeyPath("ed25519")), 0o755); err != nil {
+		return errors.Wrap(err, "sftp/server: could not create .sftp directory")
+	}
+	o, err := os.OpenFile(c.PrivateKeyPath("ed25519"), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o600)
+	if err != nil {
+		return err
+	}
+	defer o.Close()
+
+	privBytes, err := x509.MarshalPKCS8PrivateKey(key)
+	if err != nil {
+		return err
+	}
+
+	if err := pem.Encode(o, &pem.Block{
+		Type:  "PRIVATE KEY",
+		Bytes: privBytes,
+	}); err != nil {
+		return err
+	}
+	return nil
+}
+
+// PrivateKeyPath returns the path the host private key for this server instance.
+func (c *SFTPServer) PrivateKeyPath(name string) string {
+	return path.Join(c.BasePath, ".sftp", "id_"+name)
+}
+
+// A function capable of validating user credentials with the Panel API.
+func (c *SFTPServer) passwordCallback(conn ssh.ConnMetadata, pass []byte) (*ssh.Permissions, error) {
 	request := remote.SftpAuthRequest{
-		Type:          t,
 		User:          conn.User(),
-		Pass:          p,
+		Pass:          string(pass),
 		IP:            conn.RemoteAddr().String(),
 		SessionID:     conn.SessionID(),
 		ClientVersion: conn.ClientVersion(),
+		Type:          "password",
 	}
 
-	logger := log.WithFields(log.Fields{"subsystem": "sftp", "method": request.Type, "username": request.User, "ip": request.IP})
+	logger := log.WithFields(log.Fields{"subsystem": "sftp", "username": conn.User(), "ip": conn.RemoteAddr().String()})
 	logger.Debug("validating credentials for SFTP connection")
 
 	if !validUsernameRegexp.MatchString(request.User) {
@@ -200,6 +316,51 @@ func (c *SFTPServer) makeCredentialsRequest(conn ssh.ConnMetadata, t remote.Sftp
 		return nil, &remote.SftpInvalidCredentialsError{}
 	}
 
+	if len(pass) < 1 {
+		logger.Warn("failed to validate user credentials (invalid format)")
+		return nil, &remote.SftpInvalidCredentialsError{}
+	}
+
+	resp, err := c.manager.Client().ValidateSftpCredentials(context.Background(), request)
+	if err != nil {
+		if _, ok := err.(*remote.SftpInvalidCredentialsError); ok {
+			logger.Warn("failed to validate user credentials (invalid username or password)")
+		} else {
+			logger.WithField("error", err).Error("encountered an error while trying to validate user credentials")
+		}
+		return nil, err
+	}
+
+	logger.WithField("server", resp.Server).Debug("credentials validated and matched to server instance")
+	sshPerm := &ssh.Permissions{
+		Extensions: map[string]string{
+			"uuid":        resp.Server,
+			"user":        conn.User(),
+			"permissions": strings.Join(resp.Permissions, ","),
+		},
+	}
+
+	return sshPerm, nil
+}
+
+func (c *SFTPServer) publicKeyCallback(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
+	request := remote.SftpAuthRequest{
+		User:          conn.User(),
+		Pass:          "KEKW",
+		IP:            conn.RemoteAddr().String(),
+		SessionID:     conn.SessionID(),
+		ClientVersion: conn.ClientVersion(),
+		Type:          "publicKey",
+	}
+
+	logger := log.WithFields(log.Fields{"subsystem": "sftp", "username": conn.User(), "ip": conn.RemoteAddr().String()})
+	logger.Debug("validating public key for SFTP connection")
+
+	if !validUsernameRegexp.MatchString(request.User) {
+		logger.Warn("failed to validate user credentials (invalid format)")
+		return nil, &remote.SftpInvalidCredentialsError{}
+	}
+
 	resp, err := c.manager.Client().ValidateSftpCredentials(context.Background(), request)
 	if err != nil {
 		if _, ok := err.(*remote.SftpInvalidCredentialsError); ok {
@@ -210,19 +371,27 @@ func (c *SFTPServer) makeCredentialsRequest(conn ssh.ConnMetadata, t remote.Sftp
 		return nil, err
 	}
 
-	logger.WithField("server", resp.Server).Debug("credentials validated and matched to server instance")
-	permissions := ssh.Permissions{
+	if len(resp.SSHKeys) < 1 {
+		return nil, &remote.SftpInvalidCredentialsError{}
+	}
+
+	for _, k := range resp.SSHKeys {
+		storedPublicKey, _, _, _, err := ssh.ParseAuthorizedKey([]byte(k))
+		if err != nil {
+			return nil, err
+		}
+
+		if !bytes.Equal(key.Marshal(), storedPublicKey.Marshal()) {
+			continue
+		}
+
+		return &ssh.Permissions{
 			Extensions: map[string]string{
 				"uuid":        resp.Server,
 				"user":        conn.User(),
 				"permissions": strings.Join(resp.Permissions, ","),
 			},
+		}, nil
 	}
-
-	return &permissions, nil
-}
-
-// PrivateKeyPath returns the path the host private key for this server instance.
-func (c *SFTPServer) PrivateKeyPath() string {
-	return path.Join(c.BasePath, ".sftp/id_ed25519")
+	return nil, &remote.SftpInvalidCredentialsError{}
 }